FR2687218A1 - Firework with integral combustion - Google Patents

Abstract

Firework comprising a body (1) containing a burst charge (2) and illumination charges (6) which are dispersed and ignited during bursting, characterised in that the said body (1) is at least partially made of a pyrotechnic composition.

Description

The present invention relates to fireworks bombs.

  In the area of fireworks shows

  fice, safety has always posed a major problem for the fireworks operator who must reconcile the disadvantages of fallout from flaming or non-inflamed parts on the ground, with

  always more intense effects that he wishes to produce.

  One of the main causes of risk of ac-

  cidents comes from the fallout of envelope debris or

  slag belonging to materials with slow combustion.

  Generally, these fallout on the ground continue to burn and cause the start of fires that must be

  control quickly if the environment is flammable.

  The invention proposes to reduce the drawback

  spin-offs and enable realizations of envelop-

  pes directly participating in controlled pyrotechnic effects. It therefore relates to a pyrotechnic bomb comprising a body containing a bursting charge and illuminating charges, the dispersion and ignition of which are ensured during bursting, characterized in that said body is produced at least partially in one

pyrotechnic composition.

  The invention will be better understood using the

  description which follows, given only as

  example and made with reference to the accompanying drawings, in which: Fig 1 is an elevational view in section of a firework bomb according to the invention; Fig 2 is an elevational view in section of a variant of the firework bomb of Fig 1; and Figs 3 to 7 are perspective views of various shapes that the body of the bomb can take

of fireworks according to the invention.

  In Fig 1, there is shown in section a firework bomb which comprises a hollow body 1 containing

  a bursting charge 2 placed in a tube 3 in po-

  lystyrene provided with a cover 4 The tube 3 is arranged along the axis of the body 1 In the tube 3 are further

  placed ignition enhancement wicks 5.

  Inside the body and around the bursting charge 2 are arranged illuminating charges or

6 stars of a classic type.

  The bomb also comprises a felt washer 7 intended for damping at the start of the bomb,

when launched.

  A flush 8 of black powder is arranged at-

  below the felt washer 7 It is provided with an ignition device 9 connected to an ignition cord 10

arranged along the body 1.

  In this example, the ignition cord

is an electrical conductor.

  However, by ignition cord is meant everything

  whatever its nature (electrical, pyro-

  technical or other), adapted to the mode of use.

  The assembly is held by a flexible tubular envelope 11, made of kraft paper for example, closed at its two ends by links 12 and 13, the cord

  ignition 10 extending outside one of the ends

moths of envelopes 10.

  Body 1 of the following firework bomb

  the invention consists of a pyrotechnic composition

  that this pyrotechnic composition is for example a mixture of potassium, sulfur and charcoal The body is formed of three parts molded for example by compression with a hydraulic press, comprising a cylindrical lateral part 14, a cover 15 of the same average thickness that the tubular cylindrical part 14 and a thicker bottom 16 intended to provide the delay functions

  of ascension and ascending effect.

  According to a variant, the body 1 can be formed

of two pieces.

  Advantageously, the cylindrical part 14 which defines, with the bottom 16 and the cover 15, the internal cavity of the body, has an internal wall 17

  slightly tapered, flared from bottom 16 to neck

  circle 15 The ends of the cylindrical part 14 are

  engaged in shoulders 18,19, respectively provided

  ment at the periphery of the cover 15 and the bottom 16.

  The three elements are glued together.

  With the exception of the central part of the bottom 16, the exterior of the projectile thus formed is inhibited by

example with glued paper 20.

  The inhibiting material can also be

  formed by a resin or the like.

  The felt washer 7 has an axial passage 21 for communicating the powder flush

black 8 with the bottom 16 of the body 1.

  The operation of the firework bomb

  which has just been described is as follows.

  The bomb is placed in a mortar of corresponding caliber not shown. The ignition is ensured by firing using the cord 10 of the hunting 8 of black powder which propels the projectile by lighting the base of the bottom 16 of the body 1 through the passage 21 of the washer

felt 7.

  The bottom 16 burns during the ascent of the pro-

  jectile while making an ascending, at the

like a comet.

  The side wall of the body 1 being inhibited by the glued paper 20, the fire does not spread to the rest of the body. When the fire reaches the end of the cavity

  inside the body 1, it is transmitted to the wicks

  5 and the bursting load 2 which breaks the body 1 by igniting the debris of the cylindrical part 14, of the cover 15 of the unburnt part of the bottom 16 as well as

  the 6 stars contained in the body.

  The pieces of the body 1 while burning make large streaks in all directions and the stars 6 light up in a smaller radius These effects can be reinforced by increasing the thicknesses of the

  cylindrical wall 14 and cover 15.

  Except for the felt washer 7, all the cons-

  components of the fireworks bomb according to the invention are

  fuel, so that if the proportions of the constituents

  kills are well dosed, we obtain an almost complete combustion during the descent of the body debris before

that they don't reach the ground.

  For some applications, it is necessary

  avoid the comet effect when the bomb rises.

  The variant of the firework bomb according to the invention

  tion shown in Fig 2 achieves this result.

  In the bottom 16 of the bomb shown in FIG. 2 is housed an axial delay body 22 in which an ignition delay composition 23 is compressed, while the underside of the bottom 16 is inhibited for example by a sheet of glued paper. 24 In this case, the bottom 16 is

  the same thickness as the cover 15.

  For the rest, the firework bomb shown in Fig 2 is similar in all respects to

  that described with reference to Fig 1.

  During the ascent, the delay composition 23 ignited by the black powder flush 8 burns without

  drag effect and at the end of its combustion, it commu-

  fires fire at the entire bomb which then explodes causing the interior to ignite the three

  1 body elements and star illumination.

  The arrangement according to the invention also has the advantage of making it possible to modify the external and internal geometric shape of the body of the bomb and thus to obtain different but perfectly reproducible effects. In Figs 3 to 7, there are shown examples of external shapes which bodies of

  pyrotechnic bombs according to the invention.

  As can be seen in these figures, the body of the machine always has a base 30 of cylindrical shape so that it can be pulled by a mortar. On the other hand, the

  head of the bomb body can take various forms

  wheat adapted to the effects to be obtained.

  Thus in Fig 3, the body has a head 31 of cubic shape, in Fig 4, this body has a head 32 of star cross section, in Fig 5, it has a spherical head 33 and in Fig 6, the head

  34 of the body of the bomb is in the form of a warhead.

  Finally, the body shown in Fig 7 is generally cylindrical in shape and has an internal cavity

  of star cross section The cross section

  dirty from the cavity can of course take any other

appropriate forms.

  These forms are not limiting and the manufacturer

  cant can advantageously use the technological means

  suitable for the work of compositions for the

  retention of forms leading to the desired effects.

  The pyrotechnic bomb which has just been described,

  has the advantages already indicated, that of increasing

  lie about the pyrotechnic efficiency ratio between the

  pyrotechnic volume and total volume.

  It is therefore possible to obtain effects identical to those obtained with conventional machines, but

  using bombs of reduced volume.

Claims (8)

  1 Firework bomb comprising a body (1) containing a bursting charge (2) and illuminating charges (6) whose dispersion and ignition are ensured during bursting, characterized in that said body (1) is carried out at least partially in one pyrotechnic composition.   2 Firework bomb according to claim-   tion 1, characterized in that the body (1) comprises a tubular part (14), a cover (15) and a bottom (16) defining an interior cavity of the body which contains the bursting charge (2) and the charges illuminating (6), the exterior of the body (1) with the exception of at least part of the exterior surface of the bottom (16) being coated an inhibition material (20).   3 Firework bomb according to claim-   tion 2, characterized in that the inhibition material is   made up of glued paper or resin.   4 Firework bomb according to one of the   Claims 1 to 3, characterized in that a charge of   propulsion (8) provided with an igniter (9,10) is arranged near the outer surface of the bottom (16)   of the body (1) with the interposition of a washer (7)   shock at launch with passage   axial (21) of communication of the propellant charge   sive (8) with the bottom (16) of the body (1), the assembly being   contained in a flexible envelope (11).   Firework bomb according to one of the   claims 1 to 4, characterized in that the inflamma-   tor (9) of the lighting charge is provided with a firing cord (10) which extends along the lateral surface of the body (1) between said body and the envelope (11) and which   extends outside the envelope.   6 Firework bomb according to one of the   Claims 1 to 5, characterized in that the base (16)   of the body (1) has a greater thickness than the other walls of the body and thus forms a delay   ignition of the bomb during its ascent.   7 Firework bomb according to claim-   tion 6, characterized in that the bottom (16) of the body (1)   forms a drag generator on ascent.   8 Firework bomb according to one of the   Claims 1 to 4, characterized in that the bottom (16)   of the body (1) comprises an axial pyrotechnic delay (22) in which is compressed a delay composition (23) placed in communication with the propellant charge (8) via the axial passage (21) of the washer damping (7), the outer surface of the bottom (16) being inhibited.   9 Fireworks bomb according to one   conch of claims 1 to 8, characterized in that the   body of the bomb is at least partially a cylindrical external shape (30) and comprises a head (31; 32; 33; 34) whose external geometric shape is cubic, of cross section in star, spherical, in warhead, adapted to the effect to be obtained.   Firework bomb according to one   any one of claims 1 to 8, characterized in that   that the body of the bomb has an interior cavity   (35) of cross section adapted to the desired effect.